Devices and methods such as the present invention are utilized primarily when objects are spray painted in different ways. For the purpose of illuminating the invention and the problems to be solved thereby but not in any way restricting the invention, the case of spray painting carried out by a spray painting robot will hereinafter be discussed.
Automatic spray painting is used for obtaining a smooth paint finish with a paint layer homogeneously applied on an object it is very important to control the volume flow of paint to the paint nozzle with a high accuracy. For this reason, gear pumps have, until now, most often been used for feeding the paint in a conduit into a spray nozzle. This has surely resulted in highly precise control of the volume flow.
However, in some situations, the use of such pumps leads to inconveniences. There is a great need for saving paint so as to reduce the costs for the very spray painting. Also, the size of the arrangement of the gear pumps and the motors driving them needed to feed the flow of paint to the spray nozzle is generally too important and the weight thereof too high for locating an arrangement close to the spray nozzle, since this is placed on a part moving during the spray painting, such as at the end of a robot arm. This is a disadvantage, since there is a clear connection between the amount of the paint wasted and the distance between such a pump functioning as means for a regulated volume flow and the spray nozzle.